Welcome to InspirePilots.com

Join the leading DJI Inspire community for free!

Image transmission settings

Discussion in 'DJI Go App' started by hionbusa, Jan 4, 2015.

  1. hionbusa

    Joined:
    Dec 8, 2014
    Messages:
    44
    Likes Received:
    14
    Can one of Insipre 1 owners or experts elaborate on the benefits of changing the channels .
    I'm curious to see if these settings are helpful during flight .
     
  2. Tahoe Ed

    Joined:
    Dec 18, 2013
    Messages:
    426
    Likes Received:
    251
    I have mine always set on Auto. However, if you find that you are having issues on the Auto setting you can look for a clear channel and set it to that.
     
    DjiQuadzilla and hionbusa like this.
  3. slim.slamma

    Joined:
    Jan 12, 2015
    Messages:
    806
    Likes Received:
    224
    Location:
    nyc, ithaca
    Image transmission. Is it set in auto for 1.25 miles? Further distance causes me to loose image transmission. Past 1.25 miles i noticed it needs to be set to custom by selecting a channel. At 1.25 i still have max gps, and rc control. Just a week image transmission signal warning.
     
  4. The Editor

    The Editor Moderator
    Staff Member

    Joined:
    Aug 7, 2013
    Messages:
    6,718
    Likes Received:
    3,871
    My understanding is if you lower the bitrate you will get further video transmission distance.
    This would follow since higher data rates require greater transmission power.
    I am not entirely sure the Inspire transmits full HD 1080 to the ground. I have seen suggestions it is only 720p that is transmitted and variable bitrate with upscaling done in the TX and then output through the HDMI port. In fact, the more I think about it I can't see how the Inspire could be transmitting full HD 1080 video to the ground..... the bandwidth just isn't there in the 5.8ghz band.
    Obviously it isn't transmitting uncompressed HD as that just isn't feasible with the limited hardware that makes up the lightbridge system. It would mean moving 1.5Gbps!
    So that leaves either compressed HD or as I see it compressed HD ready at 720p.
    Even compressed full HD using something like H264 baseline instead of high profile would need something in the order of 9,500kbps. As R/C is limited to 100mW ERP you would only get a few hundred meters (maybe a little more with directional antenna which the Inspire doesn't possess).
    That being the case I am convinced that you are only getting a 720 feed to ground and then hardware upscaling is happening before it is output via HDMI on the back of the transmitter or fed into the iPad/tablet via USB.
    Sorry for all that, was just working that through in my head!
    OK, so upshot is.... If your video feed is breaking up at any given range, lower the bitrate for improved distance.

    Edit to this post - This has now been confirmed that the Inspire DOES NOT transmit HD to the ground (And now reflected as such on DJI's own description). As I suspected, it is 720p that is being streamed to the remote with no upscaling done before it reaches the HDMI out. DJI should not be calling this HD preview because quite simply it isn't ! Still, describing it as HD has/will sell more units obviously :rolleyes:
     
    #4 The Editor, Jan 24, 2015
    Last edited: Jan 28, 2015
  5. slim.slamma

    Joined:
    Jan 12, 2015
    Messages:
    806
    Likes Received:
    224
    Location:
    nyc, ithaca
    Ill lower it down. See if it get longer range. Like i mentioned not hitting a full mile before loosing video transmission.
     
  6. SteveT1

    Joined:
    Jul 30, 2014
    Messages:
    87
    Likes Received:
    14
    Location:
    Maryland
    Editor, Inspire uses 2.4GHz to and from the RC. 5.8GHz is only used between RC's if you have a second RC (slave) to run the camera
     
  7. LarryLeisure

    Joined:
    Mar 26, 2014
    Messages:
    35
    Likes Received:
    3
    Im on a 2 year old iPad that connects via USB to the Inspire1 and the old style Apple connector to my iPad, and my transmission is jerky and aweful. Any feedback? Just got my Inspire today, downloaded the Pilot App, upgraded software, etc...

    Flies like a champ, vid quality is great, but the feed is worthless...thank you in advance!

    Long time Vision+ user...
     
  8. Mohan

    Joined:
    Dec 25, 2014
    Messages:
    171
    Likes Received:
    51
    Location:
    Cardiff, UK
    Sorry but you need a newer ipad with a faster A7 or faster chip - ipad mini 2/3 or Air / air2

    the Ipad 1,2, 3 or 4 wont do it
     
    LarryLeisure likes this.
  9. LarryLeisure

    Joined:
    Mar 26, 2014
    Messages:
    35
    Likes Received:
    3
    Ok Thank you...just put the app on my iPhone 5s, and it works flawlessly there (don't get the 2nd window on the bottom right screen for the maps though)... any other less expensive screen recommendations other than a new iPad?
     
  10. GenesisKnight

    Joined:
    Jan 14, 2015
    Messages:
    150
    Likes Received:
    49
    Location:
    Southern Alberta
    I use an iPad Air 2 and the video is beautiful, though a little garbled if you go through tight turns. It blurs away quite a bit. Unsure if this translates to the actual video as I've yet to get home to my 28" 4k monitor to look.
    Any comparison to performance between the Galaxy Tab 8.1 for receiving/display the video feed?
     
  11. The Editor

    The Editor Moderator
    Staff Member

    Joined:
    Aug 7, 2013
    Messages:
    6,718
    Likes Received:
    3,871
    Same theory applies in the 2.4ghz band - Better picture needs higher bitrate, needs more bandwidth
     
  12. Mohan

    Joined:
    Dec 25, 2014
    Messages:
    171
    Likes Received:
    51
    Location:
    Cardiff, UK
    You could consider the Samsung Galaxy tab PRO 4 8.4 tablet
     
  13. A Story in the Sky

    Joined:
    Jan 29, 2015
    Messages:
    15
    Likes Received:
    5
    Location:
    Eastern Seaboard
    EXACT same problem on my "New iPad"
     
  14. Sheharyarali

    Joined:
    Feb 1, 2014
    Messages:
    6
    Likes Received:
    0
    Would lowering the resolution automatically change the transmission rate? I.e from 4K to 720 would result in 4Mbps(1.86mi) as opposed to 6Mbps or higher? I'm trying to figure out if we need to manually set this in the image transmission settings to get a smoother video at a greater distance or would reducing the quality from 4k to 720p automatically reduce the bandwidth?
     
  15. MindOverEye

    Joined:
    Mar 8, 2015
    Messages:
    55
    Likes Received:
    25
    Location:
    Los Angeles
    FWW - 1280x720 is considered by the ATSC to be "HD", actually anything above 720x576 counts as "HD" from a technical stand point. They really should be more clear, but...
     
  16. Kilrah

    Joined:
    Feb 3, 2015
    Messages:
    1,881
    Likes Received:
    728
    The I1 always transmits 720p whatever the camera settings, and bitrate is auto-adjusted on the fly based on signal quality (you can force it if you want).
     
    Sheharyarali and sirnikolas like this.
  17. crashburn

    Joined:
    Jan 3, 2015
    Messages:
    310
    Likes Received:
    160
    #17 crashburn, Mar 16, 2015
    Last edited: Mar 19, 2015
  18. sirnikolas

    Joined:
    Feb 24, 2015
    Messages:
    1,460
    Likes Received:
    988
    Location:
    Melbourne Australia
    Enabling hardware decode helps with stream quality.
     
  19. AtlanticAerialworX

    Joined:
    Jan 11, 2016
    Messages:
    12
    Likes Received:
    3

    Late to the show i know but hd is 720! FULL hd is 1080. They are correct in calling it hd.
     
  20. The Editor

    The Editor Moderator
    Staff Member

    Joined:
    Aug 7, 2013
    Messages:
    6,718
    Likes Received:
    3,871
    Well thanks for that - I made that post 18 months ago when the Inspire was first introduced and was working through the mechanics of the machine.

    720 is not HD in my world! :p
     
    slim.slamma likes this.